The POS integration using Liquid Barcodes Validation API is the most advanced redemption method.

The Liquid Barcodes Validation API has been designed to keep the POS integration as simple as possible for the POS developers, while maintaining high flexibility in the solutions we can offer.


Reserve and Validate coupon codes

From the POS side, at the most basic level, there are two types of requests made towards Liquid Barcodes Validation API. When a coupon code or customer ID is registered at the POS, a RESERVE request is made to do a reservation. When a transaction with reservation(s) is being closed, a VALIDATE request is made to confirm or cancel the reservation(s).





By moving complexity to Liquid Barcodes back end, we have reduced the complexity on the POS side.


Liquid Barcodes calculates personal rebates

  1. POS sends a list of products, general rebates and UserRef to Liquid Barcodes
  2. Liquid Barcodes applies personal rebates (reserves) and removes any general rebates to avoid double discounting, if applicable
  3. POS closes transaction and confirms to Liquid Barcodes
  4. Liquid Barcodes marks the coupons as used (validates)


POS calculates personal rebates

When using coupons, the following happens:

  1. When a predetermined scan range has been scanned, the POS sends a RESERVE-request to Liquid Barcodes with a simple text string (the coupon code).
  2. Liquid Barcodes replies with an array or one reservation ID and offer terms (promotional ID or a set of conditions; the best format for you depends on the way your POS handles campaigns).
  3. The POS uses these offer terms to determine product discounts. The offer terms from each reservation can only be used once.
  4. When the transaction has been completed, the POS sends validate request to Liquid Barcodes. POS must VALIDATE each reservation that has been used and CANCEL each reservation that have not been used.



Liquid Barcodes can offer POS integrations with more flexibility (click to enlarge illustration):






POS Integration scope

POS Integration questionnaire

Light POS Integration questionnaire


Using Sales service to do after sales actions

The Sales service function in the POS API allows retailers to trigger after sales actions in Liquid Barcodes back end. Primarily, the service is used to send receipt information to Liquid Barcodes. Based on the receipt Liquid Barcodes back end can trigger a wide range of actions.

The receipt needs to be linked to a unique user. The best user experience is achieved when allowing consumer to register payment method and later, when consumer makes payment with the registered payment method, the user identifier is obtained automatically and the receipt is forwarded to Liquid Barcodes for processing. This is a two step process.





Registering payment method

Customer should only have to register each payment method once. How to register payment method depends on the payment method and the specific parties involved.

Payment card, from terminal: terminal creates token and lets user input phone number. Customer receives consent SMS and token & UserID is saved in database hosted by terminal provider or third party.

Payment card, from app: user opens card registration page in app and inputs card information. It is preferable that the page is hosted by terminal provider so that card holder data is only handled by terminal provider or third party. Teminal provider stores token and user info or sends token to third party.

Mobile payment solutions: several mobile payment solutions provide built-in methods to create link between the retailer app and the mobile payment app. User may input information in mobile payment app or link using back end data transfer. When mobile payment solution is used in store, the mobile payment solutin can send User information to POS or Terminal.

Liquid Barcodes gift cards in app: no registration required.



Sending receipt to Liquid Barcodes

Based on the chosen payment method, the terminal or POS checks if a registered payment method is being used and, if yes, obtains user information and sends receipt to LB using POS Validation API – Sales service request.


Note: if customer uses Liquid Barcodes gift card in the app to pay, the link between transaction ID and user reference already exists. In this case, Liquid Barcodes can use the transaction ID to fetch the receipt from retailers receipt database, in which case the POS and Terminal does not have to do any extra requests.




You find the Liquid Barcodes Validation API here, please contact us to get password.